Abstract: A noise filtering circuit, a digital to analog converter and an electronic device are provided. The noise filtering circuit comprises a first amplifier configured to receive a bias voltage at a first input terminal, receive a bias output voltage at a second input terminal though a feedback path, and compensate for a difference between the bias voltage and the bias output voltage; a first transistor connected to an output of the first amplifier and having a gate to which an off-voltage is applied; a first capacitor connected to the first transistor; a second capacitor connected to the output of the first amplifier; a second transistor connected to the second capacitor and having a gate to which an off-voltage is applied, and a second amplifier having an input terminal connected to the first capacitor and a second input terminal connected to the second transistor.

Abstract: A delta-sigma modulator includes a first integrator configured to integrate a sum of an input signal and a first feedback signal, a second integrator configured to integrate a sum of an output value of the first integrator and a second feedback signal, a first FIR filter circuit configured to perform a first FIR filtering on an output modulation signal and a delay modulation signal and feeds back the signals to stage prior to the first integrator, and a second FIR filter circuit configured to perform a second FIR filtering on the output modulation signal and the delay modulation signal and feeds back the signals to a stage prior to the second integrator.

Abstract: A delta-sigma modulator includes a first integrator configured to integrate a sum of an input signal and a first feedback signal, a second integrator configured to integrate a sum of an output value of the first integrator and a second feedback signal, a first FIR filter circuit configured to perform a first FIR filtering on an output modulation signal and a delay modulation signal and feeds back the signals to stage prior to the first integrator, and a second FIR filter circuit configured to perform a second FIR filtering on the output modulation signal and the delay modulation signal and feeds back the signals to a stage prior to the second integrator.

Abstract: A multi-channel audio signal converting device using a time-varying digital filter, an electronic system including the same, and a method of converting an audio signal using the time-varying digital filter are provided. The multi-channel audio signal converting device includes a first signal channel and a second signal channel configured to perform analog-to-digital conversion or digital-to-analog conversion using a first clock signal; and a first time-varying filter configured to synchronize a digital audio signal synchronized with a second clock signal different from the first clock signal with the first clock signal and to input the digital audio signal to the second signal channel when digital-to-analog conversion is performed or to synchronize an output signal of the second signal channel with the second clock signal when analog-to-digital conversion is performed.

Abstract: A multi-channel audio signal converting device using a time-varying digital filter, an electronic system including the same, and a method of converting an audio signal using the time-varying digital filter are provided. The multi-channel audio signal converting device includes a first signal channel and a second signal channel configured to perform analog-to-digital conversion or digital-to-analog conversion using a first clock signal; and a first time-varying filter configured to synchronize a digital audio signal synchronized with a second clock signal different from the first clock signal with the first clock signal and to input the digital audio signal to the second signal channel when digital-to-analog conversion is performed or to synchronize an output signal of the second signal channel with the second clock signal when analog-to-digital conversion is performed.

Abstract: An active filter includes a first filter and a second filter. The first filter receives an input signal, and generates a first output signal by filtering the input signal. The second filter receives the first output signal during a time period adjusted based on a variation of a time constant of the first filter, and generates a second output signal by filtering the first output signal received during the time period. Therefore, a variation of a time constant is compensated by using post integration time control.

Abstract: An active filter includes a first filter and a second filter. The first filter receives an input signal, and generates a first output signal by filtering the input signal. The second filter receives the first output signal during a time period adjusted based on a variation of a time constant of the first filter, and generates a second output signal by filtering the first output signal received during the time period. Therefore, a variation of a time constant is compensated by using post integration time control.